Looks like I can't edit my post I don't know why.
Sorry for the double post.
Here the python3 script, which also removes the user_id from the video
Code:
import os
import shutil
headerSize = 48
def decrypt_file(encryptedFile, decryptedFile):
shutil.copy(encryptedFile, decryptedFile)
with open(decryptedFile, "r+b") as inputFile:
# Remove the user ID
videoIdEmplacement = headerSize * 2 - 3
inputFile.seek(-videoIdEmplacement, os.SEEK_END)
inputFile.write(bytes([0x00, 0x00, 0x00, 0x00]))
# Read the encrypted header
inputFile.seek(-headerSize, os.SEEK_END)
encryptedHeader = bytearray(inputFile.read(headerSize))
# Xor the header
decryptedHeader = bytes([b ^ 0x2E for b in encryptedHeader])
# Write the original file header
inputFile.seek(0, os.SEEK_SET)
inputFile.write(decryptedHeader)
inputVideoFile = r"inputVideoFile"
mp4VideoFile = r"outputVideoFile.mp4"
decrypt_file(inputVideoFile, mp4VideoFile)
Enjoy guys
Note that looking at the app, the encryption seems different on android, so just in case I'm on a PC that may differ with a mac I don't know.